September 10, 2012
Infants, Children Undergoing Heart Surgery Don’t Benefit From Controlling Blood Sugar
NIH-supported findings diverge from previous studies showing that blood sugar control benefits adults
Tight blood sugar control in infants and children undergoing heart surgery does not lower the risk of infection or improve recovery, according to a study funded by the National Institutes of Health.Infants and children who have undergone heart surgery commonly develop high blood sugar levels, which may be associated with health issues and death. Although the results of clinical trials have been mixed, some studies of adult intensive care unit (ICU) patients have found that controlling blood sugar levels with insulin resulted in fewer infections and shorter hospital stays than leaving high blood sugar levels untreated.
The Safe Pediatric Euglycemia in Cardiac Surgery (SPECS) study compared tight glycemic (blood sugar) control to standard blood sugar management in 980 children who underwent open heart surgery with heart-lung bypass. Tight glycemic control involves regularly monitoring insulin infusions to maintain normal blood sugar levels.
Compared to standard care, tight glycemic control did not reduce health care-related infections, such as pneumonia or infections of the bloodstream, urinary tract, or surgical site. Nor did it reduce the length of stay in the cardiac ICU, organ failure, or death.
The findings will be published online Sept. 7 in the New England Journal of Medicine and will appear in the print issue on Sept. 27.
"Children have often had to accept medicines and treatments based on what is known to work in adults, but treatments that benefit adults do not necessarily benefit children," said Michael Lauer, M.D., director of the Division of Cardiovascular Sciences in the NIH's National Heart, Lung, and Blood Institute (NHLBI), which supported the study. "This study underscores the importance of pediatric clinical research."
During the SPECS study, which was conducted at the Harvard Medical School, Boston Children's Hospital, and the University of Michigan C.S. Mott Children's Hospital in Ann Arbor, participants from birth to 36 months old were randomly assigned to either a tight glycemic control group or a standard ICU care group and followed for up to 30 days. The tight glycemic control group received insulin to maintain normal blood sugar levels, while the standard care group did not receive insulin. Both groups underwent continuous monitoring for hypoglycemia, or low blood sugar. Participants in the tight glycemic control group quickly (in about six hours) achieved normal blood sugar levels with few cases of severe hypoglycemia.
"Our protocol achieved tight and effective glycemic control, but that did not improve the children's health outcomes," said Michael Agus, M.D., at Boston Children's Hospital and the study's principal investigator. "Further studies may still show that this therapy benefits a different patient population."
Dr. Agus is following up with a subset of the study participants as they turn 1 year old and as they turn 3 years old to find out whether actively managing blood sugar levels after surgery has any long-term effects.
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